iDVD '09 (7.x): About iDVD encoding settings
Two primary factors affect video quality on your burned DVD. One is the quality of your source material. Lower-resolution movies, such as QuickTime movies downloaded from the Internet, or VHS video, will render lower-quality results than video taken with a DV or HDV camcorder and edited in video editing software such as iMovie, Final Cut Express, or Final Cut Pro.
The other factor is how your video is encoded. Before your project can be burned to a DVD, iDVD “encodes” the video. There are three possible encoding settings, and which you choose depends on factors such as the length of your project and how much time you have to burn your project.
The encoding settings in iDVD are the following:
When you select Best Performance, iDVD encodes your video in the background as you’re working on your project instead of waiting until you burn it. This can significantly reduce the amount of time it takes to create a finished DVD. This is a good choice if your project is an hour or less in duration (for a single-layer disc). You’ll finish your project more quickly, and the encoding quality will be excellent for the amount of video you have.
Best Performance encodes your video at a preset bit rate that produces great quality for projects that can easily fit on your disc. If you have a larger project that needs to be squeezed onto a disc, you should select one of the other encoding options.
This is the best encoding option for larger projects that are between 1 and 2 hours long (for a single-layer disc). With this setting, iDVD chooses the best bit rate possible for the amount of data you need to fit onto your disc. It’s the only option that “squeezes” all the data onto a disc at a bit rate that ensures a high video quality in your burned DVD. Because iDVD does not encode in the background with this option, it takes longer to burn your disc. The encoding process begins when you burn the DVD instead of when you start working on your project.
The Professional Quality option uses advanced technology to encode your video, resulting in the best quality of video possible on your burned DVD. You can select this option regardless of your project’s duration (up to 2 hours of video for a single-layer disc and 4 hours for a double-layer disc). Because Professional Quality encoding is time-consuming (requiring about twice as much time to encode a project as the High Quality option, for example) choose it only if you are not concerned about time.